I just knew someone would try to answer all of those "hypothetical" questions. Of course, you were off somewhat on most counts, but that doesn't reduce the fun.
#1 - Yes it has to be affected by riding style and aggressiveness, but it also has to do with the road surfaces being ridden on, tire pressures, ambient temperatures, weight load being carried, and a plethora of other variables.
#2 - The reason is because the "10" in a 10W40 oil rating describes how well the multi-vis oil flows at a low temperature
as compared to a straight weight oil also at that temperature. It only flows as well as a straight 10W oil. But the 10W oil will be pretty thick at low temps also.
Likewise, the second number describes how well the multi-vis oil flows, or more accurately how little it thins out, at higher engine operating temperatures. It retains as much viscosity at full operating temps as a straight 50W oil does. But the 50W oil is thinner at high temps than low temps also.
The multivis oil will be
considerably thinner at operating temperatures than it is at cold start temperatures.
But it will not be as thick as the 50W at cold temps, nor will it be as thin as the 10W at high temps.
Clear as mud right?
#3 - The true meaning of life is: "The condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death." Anything more is merely an abstract figment of your overactive imagination.
#4 - By answering these supposedly hypothetical questions, you have helped to prove that there
are no hypothetical questions. So what does that mean? Not much.